• 한국주조공학회지
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• 제30권1호
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• pp.5-13
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• 2010

This article aims to introduce the synchrotron radiation for its utilization in the casting and solidification fields as an unique tool for observation of real time phenomena of molten metal during solidification. General features of the synchrotron radiation were briefly introduced for readers in the casting and solidification fields, with no background regarding to synchrotron radiation. And basic principles of imaging technologies using synchrotron light for in-situ observation of molten metal were explained together with exemplary research works, which were reported on the casting and solidification fields in recent years. As a practical guide, real time observation of Al-Si casting alloy was introduced with experimental facilities, image acquisition, and processing together with representative results.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 하계종합학술대회 논문집(1)
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• pp.173-176
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• 2001

Several dielectric as well as conducting cylinders buried in the lossy half space are reconstructed from the scattered fields measured along the interface between the air and the lossy ground. Iterative inversion method by using the hybrid optimization algorithm combining the genetic and the Levenberg-Marquardt algorithm enables us to find the positions, the sizes, and the medium parameters such as the permittivities and the conductivities of the buried cylinders as well as those of the background lossy half space. Illposedness of the inversion caused by the errors in the measured scattered fields are regularized by filtering the evanescent modes of the scattered fields out.

• Wind and Structures
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• 제11권3호
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• pp.241-256
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• 2008

This paper adopts autoregressive (AR) model to simulate the wind velocity of spatial three-dimensional fields in accordance with the time and space dependent characteristics of the 3-D fields. Based on the built MATLAB programming, this paper discusses in detail the issues of the AR model deduced by matrix form in the simulation and proposes the corresponding solving methods: the over-relaxation iteration to solve the large sparse matrix equations produced by large number of degrees of freedom of structures; the improved Gauss formula to calculate the numerical integral equations which integral functions contain oscillating functions; the mixed congruence and central limit theorem of Lindberg-Levy to generate random numbers. This paper also develops a method of ascertaining the rank of the AR model. The numerical examples show that all those methods are stable and reliable, which can be used to simulate the wind velocity of all large span structures in civil engineering.

• 한국기술혁신학회:학술대회논문집
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• 한국기술혁신학회 2000년도 추계 학술대회(The 2000 Autumn Conference of korea Technology Inovation Society)(한국기술혁신학회)
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• pp.109-121
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• 2000

In the knowledge based economy, it's important to know the place where the proper knowledge locates as well as to produce the creative knowledge. This paper intends to clear up the linkage structure between research fields and its application areas. 2,135 proposals submitted to Korea Science and Engineering Foundation were analyzed to investigate the relationship between research fields and application areas. The results are as follows; first, 51.8% of the basic research is devoted to the advancement of knowledge, second, 40.8% of that is applicable to the industry, third, 49.9% of engineering and 20.2% of natural science research is applicable to the industry.

• Journal of Magnetics
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• 제8권2호
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• pp.79-84
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• 2003

Finite element analysis showed that strong magnetic fields were distributed around the arc furnace where the strongest magnetic fields were generated around the three phase cables. The second and third strongest fields near the arc furnace were found to be generated around the electrodes and the mast-arms, respectively. The generated field intensities were greatly influenced by the mast arm structure of the arc furnace as well as the phase differences and operation currents of the supplied power, Magnetic field decay patterns around the arc furnace could be smoothly fitted by this equation of exponential formula, H=H$0_$+Ae$^{\frac{r}{t}}$. These results revealed that magnetic field intensities around the arc furnace could be estimated at any 3-dimensional position using finite element method (FEM).

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 추계학술대회 논문집 전기물성,응용부문
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• pp.162-164
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• 2006

There are concern on possible health effects from exposure to electric and magnetic fields. One reflection of this concern is the considerable controversy, delay, and cost increases involved in the construction of utility lines and facilities. To meet such challenges, in this paper we investigated magnetic fields reduction techniqies such as general compaction, in-span compaction, cruciform, vertical, 3way splits phase, and 4way splits phase. As results, we found 1 spacer in-span compaction was appropriate in Korea in view of effectiveness and economy.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 추계학술대회 논문집 학회본부
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• pp.212-214
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• 1994

At recent time, superconducting technology makes it possible to develop various devices using strong magnetic fields. As increasing with devices using high magnetic fields, magnetic shielding technology is essential in order to get high efficiency. Therefore it is necessary to establish production method and clear characteristics of suitable shielding materials. Usually, ferromagnetic metal has been used for shielding of high magnetic fields up to the present time. Instead of heavy ferromagnetic metal, we can acquire better upgraded shielding system by using of very light superconducting thin film that has a perfect diamagnetism. We would like to study basic characteristics of NbTi thin film produced by RF sputtering, investigated morphology and crystal structure of NbTi thin film by SEM and XRD, identified superconductivity measuring by critical current.

• 반도체디스플레이기술학회지
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• 제22권1호
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• pp.118-123
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• 2023

Partially magnetized capacitively coupled plasma (CCP) sources are investigated using a two-dimensional kinetic simulation code named EDIPIC-2D. A converging numerical solution was obtained for CCP with a 60 MHz power source, while properly capturing the dynamics of electrons and power absorption over a single RF period. The effects of magnetic fields with different orientations were evaluated. Axial magnetic fields caused changes in the spatial distribution of plasma density, affecting the loss channel. Transverse magnetic fields enhanced stochastic heating near the powered electrode, leading to an increase in plasma density while the significant E×B drift loss compensated for this rise.

• 대한수학회지
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• 제26권2호
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• pp.195-201
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• 1989

• 한국어업기술학회:학술대회논문집
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• 한국어업기술학회 1996년도 수산관련공동학술대회발표요지집
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• pp.304-307
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• 1996